1. Field of the Invention
This invention relates to a pulse combustion apparatus which can be used effectively as a source of heat for, for example, a hot water supply system of the type in which heated water can be stored.
2. Description of the Prior Art
There is known a pulse combustion apparatus having a combustion chamber in which a mixture of fuel gas and air repeats explosion and combustion in a pulsating way. A typical example of the known apparatus is shown in FIG. 8. It includes a gas distributor 4' projecting into a mixing chamber 3' which is connected to a combustion chamber not shown through a flame trap 2'. The gas distributor 4' is defined at one end of a gas valve housing 11' extending from a gas chamber 10' and has a plurality of nozzle openings 5'. A gas flapper valve V.sub.1 ' is provided in the gas valve housing 11' toward its end which is remote from the gas distributor 4'. An air flapper valve V.sub.2 ' has an air plate 17' on which the gas valve housing 11' is supported adjacent to the gas distributor 4'.
In the known apparatus shown in FIG. 8, however, the gas distributor 4' forms an integral part of the gas valve housing 11' and the nozzle openings 5' are provided only through the circumferential wall of the gas distributor 4'. Therefore, the position of the gas distributor 4' in the mixing chamber 3' is fixed and unadjustable, and the directions in which the nozzle openings 5' are directed are also fixed and unadjustable. This disables the apparatus to be equally useful for burning various kinds of gas having different rates of combustion. The gas which is supplied through the gas distributor 4' is completely mixed with air in the mixing chamber 3'. This presents a problem particularly when the gas which is employed is one which is highly ignitable and burns rapidly, such as town gas having a high hydrogen content (e.g. gas known as 6C or 5C). If a mixture of such gas and air is supplied into the combustion chamber through the flame trap 2', a flame is likely to enter the flame trap 2' and cause a backfire resulting in the occurrence of combustion only in a limited area, or diffused combustion is likely to occur near the outlet of the flame trap 2'. There is, therefore, every likelihood that no stable combustion may be obtained continuously.